1. Field of the Invention
The present invention is related to the field of wide area network (WAN) and local area network (LAN) communication methods, devices and systems. In particular, the present invention relates to WAN/LAN communication methods, devices and systems for cargo, containerized cargo, and high value asset tracking and management.
2. Discussion of the Background
Cargo items are transported through different regions of the world using various modes of transportation. It is common for a particular cargo item to be transported through one or more different geographic regions or political regions as it is transported from a source location to a destination location. Further, a party with an interest in the cargo items is frequently interested in managing cargo item data before, during and after this transportation. Cargo management tasks typically include at least tracking the location of the cargo item from a tracking location. Cargo management systems have been proposed that use WAN/LAN technology for cargo item tracking.
An example of a background cargo item tracking system, shown in FIG. 7, includes WAN transmitters 702/708 that communicate with an orbital satellite 700 via WAN links 714/716. Each WAN transmitter 702/708 receives information about the first and second cargo items 706/712 via first and second cargo sensors 704/710, and each WAN transmitter 702/708 sends the received cargo item information to a remote tracking location 714 via an orbital satellite 700. However, this background cargo tracking system only includes a remote management feature and does not include a local management feature that would provide a tracking or a management function for a user located near the cargo, without receiving information through the orbital satellite. Further, to effectively send information from WAN transmitters 702/708 to satellite 700, each of the WAN transmitter's 702/708, and therefore each of the cargo items, are physically situated with adequate clearance from obstacles such that a satellite radio signal may be transmitted without signal degradation. In situations where cargo items are stacked on top of each other, or are located in an obstructed area such as a ship cargo hold or truck container, there is a problem of physically situating each cargo item with adequate clearance from obstacles.
FIG. 8 shows a second background cargo item tracking system that includes wireless LAN (WLAN) transmitters 806/808 that receive information about first and second cargo items 814/816 from first and second cargo sensors 810/812. The first and second WLAN transmitters 806/808 transmit this information to local management station 818 using WLAN signals 826/824 and to WLAN receiver 804 using WLAN signals 820 and 822. WLAN signals 820/822 are signals according to a background wireless LAN communication standard, such as IEEE 802.11, which uses a first frequency spectrum. A WAN transmitter 802 receives the cargo item information from the WLAN receiver 804 and transmits the cargo information to an orbital satellite 800 using WAN signal 828 and to remote management location 822 via communication link 830. WAN signal 828 is according to a background WAN signal communication standard, such as HDLC, which uses a second frequency spectrum.
However, the background cargo tracking systems also do not adequately address several additional problems. Each of the geographic regions (e.g., mountain region, ocean region, etc. . . . ) or political regions (e.g., separately administered locality, state, nation, etc. . . . ) through which the cargo items are transported may differently require or regulate the communication spectrum allocated for the purposes of LAN communication. For example, communication according to the wireless LAN communication standard IEEE 802.11 is not allowed in all political regions of the world.
Further, each mode of transportation (e.g., truck, rail, car, air, ship, etc. . . . ) and packaging arrangement (e.g., container, palette, case, etc. . . . ) employed to transport the cargo may further limit the available spectra. For example, when transporting cargo items by truck through a mountain region of a first nation, a first LAN communication spectrum may be preferred or required; however, when transporting cargo items within stacked rail containers through an ocean region on a ship, a second LAN communication spectrum may be preferred or required. Thus, background systems also do not adequately address the problem of operating within different modes of transportation, packaging arrangements and regions.
In addition, cost and complexity of background LAN communication devices used to communicate cargo item information are high due to the need for supporting various different LAN communication spectra to communicate in different regions and packing arrangements.